The present invention relates to an arrangement for buoy loading of hydrocarbons at sea, comprising a buoy means which is anchored to the sea floor by means of mooring lines and is connected to at least one riser line and is arranged to be received in a seat in a vessel for rotation with respect to the vessel about a generally vertical axis, said riser line being in flow communication with a lower connector member which is arranged on the buoy means and fitting together with an upper connector member arranged in the vessel, a flow communication being arranged between the upper connector member and one side of a swivel means, the other side of which being connected to a pipe system in the vessel.
Such an arrangement is known, e.g., from Norwegian patent No. 167.906. When used in rough weather areas, e.g., in the North Sea, the vessel will be moving all the time in order to assume the most favourable direction for meeting waves, wind and current. These movements cause frequent movements in the swivel means, which therefore is worn relatively quickly and becomes a critical element as regards the regularity of the arrangement. This problem becomes even greater if one wishes to connect further riser lines or injection lines to the ship because, in that case, the swivel will need more channels and becomes correspondingly complicated.